package com.zxing.view;
	/*
	 * Copyright (C) 2008 ZXing authors
	 *
	 * Licensed under the Apache License, Version 2.0 (the "License");
	 * you may not use this file except in compliance with the License.
	 * You may obtain a copy of the License at
	 *
	 *      http://www.apache.org/licenses/LICENSE-2.0
	 *
	 * Unless required by applicable law or agreed to in writing, software
	 * distributed under the License is distributed on an "AS IS" BASIS,
	 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	 * See the License for the specific language governing permissions and
	 * limitations under the License.
	 */


import android.content.Context;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.Typeface;
import android.util.AttributeSet;
import android.view.View;

import com.google.zxing.ResultPoint;
import com.qf.scanlibrary.R;
import com.zxing.camera.CameraManager;

import java.util.Collection;
import java.util.HashSet;

	/**
	 * This view is overlaid on top of the camera preview. It adds the viewfinder
	 * rectangle and partial transparency outside it, as well as the laser scanner
	 * animation and result points.
	 * 
	 */
	public final class ViewScan extends View {
		

		private static final String TAG = "log";
		/**
		 * 刷新界面的时间
		 */
		private static final long ANIMATION_DELAY = 10L;
		private static final int OPAQUE = 0xFF;

		/**
		 * 四个绿色边角对应的长度
		 */
		private int ScreenRate;
		
		/**
		 * 四个绿色边角对应的宽度
		 */
		private static final int CORNER_WIDTH = 10;
		/**
		 * 扫描框中的中间线的宽度
		 */
		private static final int MIDDLE_LINE_WIDTH = 6;
		
		/**
		 * 扫描框中的中间线的与扫描框左右的间隙
		 */
		private static final int MIDDLE_LINE_PADDING = 5;
		
		/**
		 * 中间那条线每次刷新移动的距离
		 */
		private static final int SPEEN_DISTANCE = 5;
		
		/**
		 * 手机的屏幕密度
		 */
		private static float density;
		/**
		 * 字体大小
		 */
		private static final int TEXT_SIZE = 16;
		/**
		 * 字体距离扫描框下面的距离
		 */
		private static final int TEXT_PADDING_TOP = 30;
		
		/**
		 * 画笔对象的引用
		 */
		private Paint paint;
		
		/**
		 * 中间滑动线的最顶端位置
		 */
		private int slideTop;
		
		/**
		 * 中间滑动线的最底端位置
		 */
		private int slideBottom;
		
		private Bitmap resultBitmap;
		private final int maskColor;
		private final int resultColor;
		
		private final int resultPointColor;
		private Collection<ResultPoint> possibleResultPoints;
		private Collection<ResultPoint> lastPossibleResultPoints;

		boolean isFirst;
		
		public ViewScan(Context context, AttributeSet attrs) {
			super(context, attrs);
			
			density = context.getResources().getDisplayMetrics().density;
			//将像素转换成dp
			ScreenRate = (int)(20 * density);

			paint = new Paint();
			Resources resources = getResources();
			maskColor = resources.getColor(R.color.viewfinder_mask);
			resultColor = resources.getColor(R.color.result_view);

			resultPointColor = resources.getColor(R.color.possible_result_points);
			possibleResultPoints = new HashSet<ResultPoint>(5);
		}

		@Override
		public void onDraw(Canvas canvas) {
			//中间的扫描框，你要修改扫描框的大小，去CameraManager里面修改
			Rect frame = CameraManager.get().getFramingRect();
			if (frame == null) {
				return;
			}
			
			//初始化中间线滑动的最上边和最下边
			if(!isFirst){
				isFirst = true;
				slideTop = frame.top;
				slideBottom = frame.bottom;
			}
			
			//获取屏幕的宽和高
			int width = canvas.getWidth();
			int height = canvas.getHeight();

			paint.setColor(resultBitmap != null ? resultColor : maskColor);
			
			//画出扫描框外面的阴影部分，共四个部分，扫描框的上面到屏幕上面，扫描框的下面到屏幕下面
			//扫描框的左边面到屏幕左边，扫描框的右边到屏幕右边
			canvas.drawRect(0, 0, width, frame.top, paint);
			canvas.drawRect(0, frame.top, frame.left, frame.bottom + 1, paint);
			canvas.drawRect(frame.right + 1, frame.top, width, frame.bottom + 1,
					paint);
			canvas.drawRect(0, frame.bottom + 1, width, height, paint);
			
			

			if (resultBitmap != null) {
				// Draw the opaque result bitmap over the scanning rectangle
				paint.setAlpha(OPAQUE);
				canvas.drawBitmap(resultBitmap, frame.left, frame.top, paint);
			} else {

				//画扫描框边上的角，总共8个部分
				paint.setColor(Color.GREEN);
				canvas.drawRect(frame.left, frame.top, frame.left + ScreenRate,
						frame.top + CORNER_WIDTH, paint);
				canvas.drawRect(frame.left, frame.top, frame.left + CORNER_WIDTH, frame.top
						+ ScreenRate, paint);
				canvas.drawRect(frame.right - ScreenRate, frame.top, frame.right,
						frame.top + CORNER_WIDTH, paint);
				canvas.drawRect(frame.right - CORNER_WIDTH, frame.top, frame.right, frame.top
						+ ScreenRate, paint);
				canvas.drawRect(frame.left, frame.bottom - CORNER_WIDTH, frame.left
						+ ScreenRate, frame.bottom, paint);
				canvas.drawRect(frame.left, frame.bottom - ScreenRate,
						frame.left + CORNER_WIDTH, frame.bottom, paint);
				canvas.drawRect(frame.right - ScreenRate, frame.bottom - CORNER_WIDTH,
						frame.right, frame.bottom, paint);
				canvas.drawRect(frame.right - CORNER_WIDTH, frame.bottom - ScreenRate,
						frame.right, frame.bottom, paint);

				
				//绘制中间的线,每次刷新界面，中间的线往下移动SPEEN_DISTANCE
				slideTop += SPEEN_DISTANCE;
				if(slideTop >= frame.bottom){
					slideTop = frame.top;
				}
				canvas.drawRect(frame.left + MIDDLE_LINE_PADDING, slideTop - MIDDLE_LINE_WIDTH/2, frame.right - MIDDLE_LINE_PADDING,slideTop + MIDDLE_LINE_WIDTH/2, paint);
				
				
				//画扫描框下面的字
				paint.setColor(Color.WHITE);
				paint.setTextSize(TEXT_SIZE * density);
				paint.setAlpha(0x40);
				paint.setTypeface(Typeface.create("System", Typeface.BOLD));
				canvas.drawText(getResources().getString(R.string.scan_text), frame.left, (float) (frame.bottom + (float)TEXT_PADDING_TOP *density), paint);
				
				

				Collection<ResultPoint> currentPossible = possibleResultPoints;
				Collection<ResultPoint> currentLast = lastPossibleResultPoints;
				if (currentPossible.isEmpty()) {
					lastPossibleResultPoints = null;
				} else {
					possibleResultPoints = new HashSet<ResultPoint>(5);
					lastPossibleResultPoints = currentPossible;
					paint.setAlpha(OPAQUE);
					paint.setColor(resultPointColor);
					for (ResultPoint point : currentPossible) {
						canvas.drawCircle(frame.left + point.getX(), frame.top
								+ point.getY(), 6.0f, paint);
					}
				}
				if (currentLast != null) {
					paint.setAlpha(OPAQUE / 2);
					paint.setColor(resultPointColor);
					for (ResultPoint point : currentLast) {
						canvas.drawCircle(frame.left + point.getX(), frame.top
								+ point.getY(), 3.0f, paint);
					}
				}

				
				//只刷新扫描框的内容，其他地方不刷新
				postInvalidateDelayed(ANIMATION_DELAY, frame.left, frame.top,
						frame.right, frame.bottom);
				
			}
		}

		public void drawViewfinder() {
			resultBitmap = null;
			invalidate();
		}

		/**
		 * Draw a bitmap with the result points highlighted instead of the live
		 * scanning display.
		 * 
		 * @param barcode
		 *            An image of the decoded barcode.
		 */
		public void drawResultBitmap(Bitmap barcode) {
			resultBitmap = barcode;
			invalidate();
		}

		public void addPossibleResultPoint(ResultPoint point) {
			possibleResultPoints.add(point);
		}

	}



